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Biomedical subjects

R R Lemon

Publications and source records attributed to R R Lemon.

14 recordsLinked to original sources
PubMed1998

Combining treatment modalities for tetracycline-discolored teeth.

Tetracycline-discolored teeth that are to be restored by porcelain laminate veneers present a clinical challenge. Successfully bleaching such teeth prior to veneering will permit the clinician and technician to overcome the technical difficulties associated with masking dark teeth. This article describes a combined treatment modality in which the teeth are bleached after the preparation for porcelain laminate veneers.

Carbamide Peroxide↗
PubMed1997

Coronal leakage: effects of smear layer, obturation technique, and sealer.

Coronal microleakage may be a major factor in the etiology of treatment failure. This study examined the effect of obturation technique, sealer, and the presence of smear layer on coronal microleakage. Two hundred extracted human teeth were assigned to 20 treatment groups. Groups were examined with the smear layer present or smear layer removed (17% REDTA). Access cavities were exposed to artificial saliva then Pelikan Ink. Teeth were cleared and linear dye penetration measured. When all groups with the smear layer removed were compared with all groups with the smear layer present, significantly less leakage was seen when the smear layer was removed. Ultrafil displayed significantly more leakage than all other groups. Vertical compaction of lateral condensation and Thermafil obturations significantly reduced leakage. AH-26 displayed significantly less leakage than Roth's 811 sealer. These results indicate that removal of the smear layer, the use of AH-26, and vertical compactin have cumulative effects in reducing coronal leakage.

Analysis of Variance↗
PubMed1996

Current trends in endodontic treatment: report of a national survey.

The authors surveyed 360 general dentists and 291 endodontists to obtain information on routine, nonemergency endodontic treatments adapted to clinical practice. Frequent practices and recent advances in treatment modalities-including instrumentation, obturation, intracanal preparations, medications and restorations-are highlighted.

Analgesics↗
PubMed1995

Coronal microleakage in conservatively restored endodontic access preparations.

This study evaluated the coronal microleakage of endodontic access preparations restored with glass ionomer cement (GIC), composite resin (CR), or the "sandwich" (GIC/CR) techniques. The size of access preparation for 32 freshly extracted maxillary premolars was standardized by using a stainless steel template. The teeth were randomly divided into three experimental groups of 10 teeth and one group of two control teeth. Group One: light cured glass ionomer cement, Vitra Bond (3M Dental Products Division, St. Paul, MN). Group Two: composite resin, Silux Plus (3M Dental Products Division, St. Paul, MN). Group Three: "sandwich" technique, consisting of a 3 mm glass ionomer cement base and composite resin restoring the remaining access. The restorative materials were placed incrementally and cured from the facial, lingual and occlusal planes for 20-second intervals. The teeth were thermocycled for 24 hours, immersed in methylene blue dye for 48 hours, and then sectioned to measure dye penetration. This study differed substantially from similar leakage studies. The "sandwich" (GIC/CR) and the composite resin restorations allowed significantly less coronal leakage than the glass ionomer cement restorations. Although not statistically significant, less leakage was measured with the "sandwich" restoration than the composite resin restoration.

Bicuspid↗
PubMed1994

Effectiveness of various medications on postoperative pain following complete instrumentation.

The root canals of 588 consecutive nonsurgical patients with varying levels of pain were completely instrumented in 10 endodontic practices and 4 endodontic graduate programs. The participants were sequentially assigned to one of nine medications and a placebo. The severity of pain was assessed by the visual analog scale for 72 h following instrumentation. Among all of the parameters studied, three factors (preoperative pain, apprehension, and types of medication) were found to be significant in determining postinstrumentation pain. An association was found between the intensity of pre-and postoperative pain. As the intensity of preoperative pain increased, the chances for more severe postoperative pain increased (p < 0.0001). In addition, an association between the presence of apprehension before any treatment and postoperative pain was also noted (between 0.012 < p < 0.047). Examination of the time-effect curves for various medications in patients with no mild pain showed no statistical significant difference between the effectiveness of different medications and placebo. However, a multiple comparison of the effectiveness of various medications and placebo on patients in moderate and severe preoperative pain showed that ibuprofen, ketoprofen, erythromycin base, penicillin, and methylprednisolone plus penicillin were more effective than placebo within the first 48 h following complete instrumentation.

Acetaminophen↗
PubMed1993

Ferric sulfate hemostasis: effect on osseous wound healing. Left in situ for maximum exposure.

Ferric sulfate solution is an accepted soft tissue hemostatic agent for use in dermatology and dentistry. This study was designed to test its effect on osseous healing when used during surgery to control osseous hemorrhage. Standardized osseous defects were created bilaterally in the naturally edentulous zone in rabbit mandibles. The control site was sutured immediately after clot formation in the defect. The contralateral experimental site received ferric sulfate application until complete hemostasis was achieved. The defect was filled with ferric sulfate solution to maximize any effect on healing and then closed with sutures. The experimental and control specimens were examined histologically after 18 and 46 days and scored for healing. Statistical analysis by Wilcoxon signed rank test showed significant adverse effects on osseous healing when ferric sulfate solution was left in situ.

Alveolar Process↗
PubMed1993

Ferric sulfate hemostasis: effect on osseous wound healing. II. With curettage and irrigation.

Hemorrhage control is often a problem for the clinician during osseous surgery. Ferric sulfate is an effective hemostatic agent, but with prolonged application to an osseous defect can cause persistent inflammation and delayed healing. The purpose of this investigation was to evaluate the effectiveness of ferric sulfate as a hemostatic agent and to determine its effect on healing after thorough curettage and irrigation from osseous surgical wounds. Standard size osseous defects were created bilaterally in the mandibles of rabbits. Ferric sulfate was placed in one defect until hemostasis was obtained; the contralateral defect was allowed to fill with blood and clot. After 5 min both defects were curetted and irrigated. The repair of the defects was evaluated histologically at 18 and 46 days. There were no significant differences between the ferric sulfate-treated defects and the untreated controls. When adequately curetted and irrigated from the surgical site prior to closure, ferric sulfate did not cause persistent inflammation or delay osseous repair in comparison to controls.

Alveolar Process↗
PubMed1992

Nonsurgical repair of perforation defects. Internal matrix concept.

The internal matrix concept of perforation repair offers distinct advantages over classic techniques. The biocompatible matrix allows control of the repair material. The technique sensitivity involved with placement of the repair material is reduced and contamination of the restorative material with hemorrhage is prevented. In accessible locations perforations can be repaired predictably and, by comparison, the prognosis is improved greatly. Fewer surgeries or surgical alterations of teeth will be necessary, thus reducing the cost of treatment. A higher percentage of existing crowns can be salvaged if surgical alteration of the tooth is prevented. Microsurgical techniques currently are being developed and researched that may allow nonsurgical repair of inaccessible perforations. The scope of endodontic therapy, therefore, will be expanded.

Biocompatible Materials↗
PubMed1991

Bleaching and restoring endodontically treated teeth.

Internal, or "walking," bleaching has been successfully used in dentistry for many years to reverse stains associated with nonvital teeth. The procedure is predictable for color change but is not without problems. Current research has identified the cause of cervical resorption, which has been associated with internal bleaching. Second-generation esthetic bonding materials theoretically should provide an improved seal at the tooth-restorative interface, but the limited current research does not support this contention. A suggested method for internal bleaching and restoring the access cavity is presented.

Animals↗
PubMedDate not supplied

How tough is that root canal?

It is not uncommon to be faced with difficult treatment planning decisions when a patient presents with an endodontic problem during a routine day in the practice of general dentistry. Signs and symptoms of pulpal or periapical disease dictate the need for decision-making, and frequently the result of that decision is magnified by the patient experiencing severe pain. Our purpose is to present a link between case selection based on risk factors and the self-assessment of the dentist regarding his or her ability or motivation to treat a given case.

Attitude of Health Personnel↗